<!DOCTYPE html>
<html class="reftest-wait">
<link rel="help" href="https://drafts.csswg.org/css-backgrounds-3/#background-color">
<link rel="match" href="one-element-transition-with-delay-ref.html">
<style>
.container {
  width: 100px;
  height: 100px;
  background-color: rgb(0, 200, 0);
  transition: background-color 200000ms steps(2) -99995ms;
}
</style>
<script src="/common/reftest-wait.js"></script>
<body>
<div class="container" id="target"></div>

<script>
// This test differs from "one-element-transition.html" because it runs the
// transition starting from the set background color, rather than using a
// delay to start in the middle of the transition. This tests a new codepath
// where the first frame of the transition has the original background color,
// which is why we need the transition fully running. Since we are using the
// step(2) in the animation, so it is enough to wait for 5ms and the animation
// should be in its mid-point, that's the time we should take screenshot.
let start_time;
function startTransition(timestamp) {
  document.getElementById('target').style.backgroundColor = "rgb(200, 0, 0)";
  requestAnimationFrame(startTimer);
}

function startTimer(timestamp) {
  start_time = timestamp;
  requestAnimationFrame(wait);
}

function wait(timestamp) {
  if (timestamp - start_time <= 5) {
    requestAnimationFrame(wait);
    return;
  }
  takeScreenshot();
}

requestAnimationFrame(startTransition);
</script>
</body>
</html>
